President Barack Obama is expected to use his budget proposal to call on Congress to overhaul the corporate tax system in a way that doesn’t generate additional revenue, a move that is sure to anger liberal Democrats in the Senate.

The White House didn't respond to requests for comment on the expected language, which several sources said would be included in the fiscal 2014 budget proposal that will be unveiled Wednesday.

Beyond calling for revenue-neutrality, it’s not clear how deeply the president’s budget will wade into the choppy waters of corporate tax reform.

The budget move is a concession of sorts by Obama, who released a framework for corporate tax reform last year that would have raised $250 billion over 10 years.

But it likely will not be enough to entice Republicans who want individual and corporate tax reform, with no overall revenue increases, done as a package. And liberal Democrats — already fuming over the administration’s plan to change the way Social Security benefits are calculated — aren’t pleased.

“Corporations are not overtaxed in America,” Sen. Tom Harkin (D-Iowa) said Tuesday. “Let’s be frank about that. We need to close a lot of loopholes and we need to raise some revenues — bottom line.”

Illinois Sen. Dick Durbin, the chamber’s No. 2 Democrat, said he “would like to see us use ... corporate tax reform to generate revenue for deficit reduction.”

“But I think the president’s budget does not take that approach,” he said. “The president’s budget is important and I’ll look at it carefully, but more important is the fact that we passed a budget resolution in the Senate.”

That legislation included $1 trillion in new revenue generated from both individuals and corporations.

Senate Finance Committee Chairman Max Baucus (D-Mont.), who is working closely with Republican House Ways and Means Committee Chairman Dave Camp on a comprehensive tax overhaul, struck a more moderate tone than some of his colleagues.

Revenue-neutral reform is “easier on corporate than it is on individual,” Baucus told POLITICO. “It just seems to fit more neatly than the other side.”

Obama has signaled his shift on corporate tax reform to lawmakers over the past several weeks. He told Republicans in closed-door meetings on Capitol Hill last month that he could back a revenue-neutral approach to corporate tax reform.

Still, his budget provides plenty of red-meat tax provisions for liberals, including a proposal to limit tax-advantaged contributions to IRAs to $3 million. That’s a direct smack at people like Obama’s former presidential rival Mitt Romney, whose IRA was valued at as much as $100 million last year.

Statutory corporate tax rates top out today at 35 percent, though many companies take advantage of generous deductions and credits to push their effective tax rates much lower.

Camp and other congressional Republicans have called for cutting corporate and individual tax rates to 25 percent.

The administration released a “framework” last year outside of the normal budget process. That document called for cutting corporate rates to 28 percent — and as low as 25 percent for manufacturers.

While the administration left most of the dirty work required to lower rates to Congress, the framework called for the elimination of oil and gas tax breaks, accounting changes and different treatment for some insurance products.

This article first appeared on POLITICO Pro at 3:12 p.m. on April 9, 2013.